Functions for display of graphics-format images in a no-frills
viewing window (an ImageWindow).
Supported image formats include GIF, JPEG, PNG and FITS,
which may be compressed.

displayBasicImage( label, loc )

Displays the file at a given location as an image
in a graphical viewer.
label may be any string which identifies the window
for display, so that multiple images may be displayed in different
windows without getting in each others' way.
loc should be a filename or URL, pointing to an image in
a format that this viewer understands.